Why don't you want to use the height attribute? I'm assuming the issue is that you want them both to be the same height, and that height should be the minimum value required to hold the larger of the two entries. If so, you will probably need to use height...
–
KendrickOct 13 '10 at 14:50

2 Answers
2

First, you should fix the bad markup (no closing quote in id="ROOT_1_0>, no closing greater than symbol on </div, et cetera) in your example HTML.

Second, I recommend specifying a min-height for both of your boxes in ems. Ems are relative to the font size of the current element, so they're expandable. If IE6 is a concern, you can specify height and overflow: auto; for just IE6.

If ROOT_1_0 and ROOT_1_1 are supposed to be next to each other (say, by changing the width and floating them), consider using faux columns.